In the art of assembling closures to containers, it has been the practice to feed the closures one at a time into intercepting relationship with respect to the finish of the containers to which they are to be applied. This normally takes place while the containers are full of a product that is to be shipped in the containers. In the case of the shipment of home-canning jars, it has been the practice in the past to package the jars for shipment separately and the closures or lids be packed separate also. It is common practice now to market the style of "home canning" lids which are formed of a disc-shaped panel that is loosely retained in an annular threaded skirt. These typically have also been packaged as separate items capable of being purchased separate from the containers.
When closures are of a one-piece construction, handling them is relatively easy; however, when they are of a two-piece construction, with the panel and skirt separate and when assembled will fall apart easily due to lack of any interlocking, putting the closures on the jars at a high speed becomes more of a task. It has been suggested by existing prior art to move the closures in inverted position with their panels down and the skirts extending upwardly from the panel and then threading them on containers that are turned upsidedown. Obviously, this system applies only to the situation where the closures are being applied to unfilled containers.
The reason for feeding closures in inverted position is to maintain the two units of the closures in assembled position. It has also been the practice in the past, to put the closures on by hand. Again, this then becomes a fairly labor-intensive-operation, and, therefore, less economical than an apparatus which will apply the two-piece closures to containers at fairly high rates of speed and with minimum maintenance required. It has also been suggested that the two-pieces of the closure be interlocked in some manner; however, this requires special tooling for the components and also will require special assembly techniques, all of which add to the expense of the closures.